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Java

Java is a high-level, general-purpose, memory-safe, object-oriented programming language.

In LiveCodes, Java runs in the browser using DoppioJVM.

Usage

Demo:

show code
import { createPlayground } from 'livecodes';

const options = {
"config": {
"activeEditor": "script",
"script": {
"language": "java",
"content": "public class BinarySearchSnippet {\n /**\n * Search an item with binarySearch algorithm.\n *\n * @param arr sorted array to search\n * @param item an item to search\n * @return if item is found, return the index position of the array item otherwise return -1\n */\n\n public static int binarySearch(int[] arr, int left, int right, int item) {\n if (right >= left) {\n int mid = left + (right - left) / 2;\n if (arr[mid] == item) {\n return mid;\n }\n\n if (arr[mid] > item) {\n return binarySearch(arr, left, mid - 1, item);\n }\n\n return binarySearch(arr, mid + 1, right, item);\n }\n return -1;\n }\n\n public static void main(String[] args) {\n int[] sortedArray = {1, 3, 5, 7, 9, 11, 13, 15};\n int itemToSearch = 7;\n\n int result = binarySearch(sortedArray, 0, sortedArray.length - 1, itemToSearch);\n\n if (result == -1) {\n System.out.println(\"Result: Item not found in the array.\");\n } else {\n System.out.println(\"Result: Item found at index -> \" + result);\n }\n }\n}\n"
},
"mode": "simple",
"editor": "auto",
"tools": {
"status": "full"
}
}
};
createPlayground('#container', options);

Communication with JavaScript

The Java code runs in the context of the result page. A few helper properties and methods are available in the browser global livecodes.java object:

  • livecodes.java.input: the initial standard input that is passed to the Java code.
  • livecodes.java.loaded: A promise that resolves when the Java environment is loaded. Any other helpers should be used after this promise resolves.
  • livecodes.java.output: the standard output.
  • livecodes.java.error: the standard error.
  • livecodes.java.exitCode: the exit code.
  • livecodes.java.run: a function that runs the Java code with new input. This function takes a string as input and returns a promise that resolves when the Java code is done running. The promise resolves with an object containing the input, output, error, and exitCode properties.

Example:

show code
import { createPlayground } from 'livecodes';

const options = {
"template": "java",
"params": {
"activeEditor": "markup"
}
};
createPlayground('#container', options);

Language Info

Name

java

Extension

.java

Editor

script

Compiler

DoppioJVM

Version

DoppioJVM: v0.5.0, which runs Java 8 JDK.

Code Formatting

Using Prettier with the Prettier Java plugin.

Live Reload

By default, new code changes are sent to the result page for re-evaluation without a full page reload, to avoid the need to reload the Java environment.

This behavior can be disabled by adding the code comment // __livecodes_reload__ to the code, which will force a full page reload. This comment can be added in the hiddenContent property of the editor for embedded playgrounds.

Starter Template

https://livecodes.io/?template=java